Abstract: From a socio-ecological perspective, a built environment that provides safe, convenient, attractive places for transportation or recreational physical activity is a prerequisite for increasing physical activity levels of the population. Support from decision-makers, including urban planners and developers, will be necessary to alter the built environment through policy change and innovative development strategies. The purposes of this mixed-method study are to develop an understanding of how built environments that are conducive to transportation and recreational physical activity can result from the planning and development process in urbanized areas. The study aims are to: 1) characterize barriers to developments that support physical activity that occur during the planning and development process from urban planners and developers and 2) develop a theoretical framework to explain the relationships among these barriers to developments that support physical activity. In depth, semi-structured interviews were conducted with twelve (12) planners from the four most populous municipalities in the Greensboro--Winston-Salem--High Point, North Carolina Combined Statistical Area and six (6) residential developers who were currently involved in one or more of these jurisdictions. Typical case sampling was used to select planners from each of the municipalities while theoretical sampling was used to select the developers. The digitally recorded interviews were transcribed and analyzed using NVivo 8. Quantitative data were analyzed using non-parametric statistics in SPSS. The study finds that the purposes of land-use regulation as defined by planners and developers do not include health promotion. Participants perceived that recreational opportunities were more important to residents than opportunities for transportation physical activity. Through the use of images, participants agreed that isolated single-use developments provided fewer opportunities for physical activity. While high density, mixed-use developments with a variety of housing and transportation choice and meaningful open space provide opportunities for physical activity, these development strategies can cause conflict during the planning and development process. Three types of conflict were identified as barriers to development strategies that promote physical activity: 1) Professional Conflict between planners and developers, 2) Resident Conflict between developers and residents, and 3) Historical Conflict within local governments. Differences in the value systems of planners, developers, and residents used to make decisions serve as catalysts for these conflicts. The theoretical framework for increased physical activity through development strategies illustrates the relationships between the development strategies, the central phenomenon of conflict, and the value systems. The findings suggest that development strategies that may promote physical activity are unlikely to be widely adopted without intervention in the development process. The theoretical framework provides guidance for selecting effective intervention strategies and targets.